Cheri-research/Toooba
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Allow a vector of translations to be remembered.

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Just do 2 for now.
This commit is contained in:
Jonathan Woodruff
2024-01-17 13:21:38 +00:00
parent 4f91e54bd2
commit 5a1ed7c57f
1 changed files with 24 additions and 7 deletions
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31
src_Core/RISCY_OOO/procs/RV64G_OOO/FetchStage.bsv
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@@ -323,6 +323,9 @@ typedef struct {
CapMem nextPc;
} TrainNAP deriving(Bits, Eq, FShow);
// "micro-TLB" size (buffer of past few translations)
typedef 2 PageBuffSize;
// ================================================================
// Functions for 'C' instruction set
@@ -530,19 +533,28 @@ module mkFetchStage(FetchStage);
end
endaction;
Reg#(Maybe#(Vpn)) buffered_translation_virt_pc <- mkReg(Invalid);
Reg#(TlbResp) buffered_translation_tlb_resp <- mkRegU;
Reg#(Vector#(PageBuffSize,Maybe#(Vpn))) buffered_translation_virt_pc <- mkReg(replicate(Invalid));
Reg#(Vector#(PageBuffSize,TlbResp)) buffered_translation_tlb_resp <- mkRegU;
Reg#(Bit#(TLog#(PageBuffSize))) buffered_translation_count <- mkRegU;
rule invalidate_buffered_translation(!iTlb.flush_done);
buffered_translation_virt_pc <= Invalid;
buffered_translation_virt_pc <= replicate(Invalid);
endrule
rule getTlbResp(iTlb.flush_done);
// Get TLB response
TlbResp tr <- tlb_server.response.get;
buffered_translation_virt_pc <= Valid(getVpn(translateAddress.first));
buffered_translation_tlb_resp <= tr;
translateAddress.deq;
// Check if, because of pipelining, we already have this vpn.
Bool found = False;
for (Integer i = 0; i < valueOf(PageBuffSize); i=i+1)
if (buffered_translation_virt_pc[i] matches tagged Valid .vpn &&& getVpn(translateAddress.first) == vpn)
found = True;
if (!found) begin
buffered_translation_virt_pc[buffered_translation_count] <= Valid(getVpn(translateAddress.first));
buffered_translation_tlb_resp[buffered_translation_count] <= tr;
buffered_translation_count <= buffered_translation_count + 1;
end
if (verbosity >= 2) $display ("%d Fetch Translate: pc: %x, ", cur_cycle, translateAddress.first, fshow (tr));
endrule
@@ -573,7 +585,12 @@ module mkFetchStage(FetchStage);
dii_pid_reg[pc_fetch1_port] <= dii_pid + (zeroExtend(posLastSupX2) + 1);
`endif
if (buffered_translation_virt_pc matches tagged Valid .vpn &&& getVpn(getAddr(pc)) == vpn) begin
// Search the last few translations to look for a match.
Maybe#(Bit#(TLog#(PageBuffSize))) m_buff_match_idx = Invalid;
for (Integer i = 0; i < valueOf(PageBuffSize); i=i+1)
if (buffered_translation_virt_pc[i] matches tagged Valid .vpn &&& getVpn(getAddr(pc)) == vpn)
m_buff_match_idx = tagged Valid fromInteger(i);
if (m_buff_match_idx matches tagged Valid .buff_match_idx) begin
let next_fetch_pc = fromMaybe(addPc(pc, 2 * (zeroExtend(posLastSupX2) + 1)), pred_next_pc);
let pc_idxs <- pcBlocks.insertAndReserve(truncateLSB(pc), truncateLSB(next_fetch_pc));
PcIdx pc_idx = pc_idxs.inserted;
@@ -588,7 +605,7 @@ module mkFetchStage(FetchStage);
Valid(compressPc(ppc_idx, validValue(pred_next_pc))) : Invalid,
decode_epoch: decode_epoch[0],
main_epoch: f_main_epoch};
start_imem_lookup(out, buffered_translation_tlb_resp);
start_imem_lookup(out, buffered_translation_tlb_resp[buff_match_idx]);
pc_reg[pc_fetch1_port] <= next_fetch_pc;
if (verbose) $display("%d Fetch1: ", cur_cycle, fshow(out), " posLastSupX2: %d", posLastSupX2);
end else begin